标题： La0.175Pr0.45Ca0.375MnO3中动力学冻结的反铁磁相在磁场作用下发生析晶的结构证据：低温高磁场X射线衍射研究 显示英文标题

标题： Structural evidence of magnetic field induced devitrification of kinetically arrested antiferromagnetic phase in La0.175Pr0.45Ca0.375MnO3: A Low-temperature high-magnetic field x-ray diffraction study

摘要： 在低温和高磁场（2K，8T）下进行了粉末X射线衍射（LTHM-XRD）测量，以研究相分离的La0.175Pr0.45Ca0.375MnO3（LPCMO）锰氧化物的结构相图。反铁磁（AFM）P21/m绝缘相在零场冷却（ZFC）从室温下降至其AFM有序温度（220K）以下时，会经历磁场诱导的转变，变为铁磁（FM）Pnma金属基态。在温度高于25K时，磁场诱导的FM Pnma相即使完全去除磁场后仍不可逆。然而，对于T（39-65K），磁场诱导的转变是部分可逆的。这种行为被归因于磁场诱导的玻璃状冻结的AFM P21/m相向FM Pnma平衡相的析晶。在零场下加热样品时，析晶的FM Pnma相大约在~39K开始转变为AFM P21/m相。我们的结果证实了该系统中存在强磁致结构耦合。基于LTHM-XTD数据构建了一个H-T相图，该相图与通过磁性测量得到的相图相似。这些结果基于一级相变的动力学冻结以及冻结相的磁场诱导析晶来解释。 显示英文摘要

摘要： The low-temperature and high-magnetic field (2K, 8T) powder x-ray diffraction (LTHM-XRD) measurements have been carried out at different temperatures (T) and magnetic fields (H) to investigate the structural phase diagram for phase separated La0.175Pr0.45Ca0.375MnO3 (LPCMO) manganite. The antiferromagnetic (AFM) P21/m insulating phase undergoes field induced transformation to ferromagnetic (FM) Pnma metallic ground state below its AFM ordering temperature (220K) in zero-field cooling (ZFC) from room temperature. At temperature greater than 25K, the field induced FM Pnma phase remained irreversible even after complete removal of field. However, for T ( 39-65K), the field induced transformation is partially reversible. This behaviour has been attributed to magnetic field induced devitrification of the glass-like arrested AFM P21/m phase to FM Pnma equilibrium phase. The devitrified FM Pnma phase starts transforming back to AFM P21/m phase around ~39K on heating the sample under zero field. Our results corroborate the evidence of strong magneto-structural coupling in this system. An H-T phase-diagram has been constructed based on LTHM-XTD data, which resembles with the one made from magnetic measurements. These results have been explained on the basis of kinetic arrest of first order phase transition and field induced devitrification of the arrested phase.